Are you looking to Install a solar PV system into your home or business but don’t know which devices you will need? Don’t worry anymore.
Solar PV system operate in the presence of inverter, charge controller, solar battery, and a solar panel. Each of this devices have different function that cannot be substituted by any other devices.
With the recent advancements in solar kits, we have devices that can perform more than one function. An example of this device is a solar inverter. Keep reading this guide to find out how this devices work.
Can you run solar inverter without battery?
A solar inverter is a small yet sophisticated device that converts Direct Current into Alternating Current. Inverters use solar batteries as reference for the charge. Normally, what happens is that a solar panel sends current to a solar battery in one direction. A solar inverter then converts the current into different potions depending on the appliance being powered.
The big question is can you this devices work in the absence of solar battery? To answer that question, we will look into different types of solar inverters and how they work.
There are two types of solar inverters: String and Micro-inverters
String Solar Inverters
These inverters come in single-phase and three-phase versions. String Solar Inverters are the commonly used inverters mostly in the USA, Australia, and Europe. They are very easy to install and low are very affordable.
These inverters are very small and can only convert current from one or two solar panels.
Both string Solar Inverters and Micro-inverters lack the capacity to store charge to power appliances. However, a new type of inverter known as a hybrid inverter can work without a solar battery.
Can a hybrid solar inverter run without batteries?
Hybrid inverters are made by merging a solar inverter and a battery inverter. This inverters can be connected to a solar battery or direct to a solar panel and an existing grid. This is possible through the two methods of installation.
Off the grid installation
When installing hybrid Inverters as an off the grid, you will need a solar panel, solar battery, hybrid inverter, and a charge controller.
On-grid solar installation without a solar battery
On-grid installation is very affordable and the most common type of solar PV system. This installation involves the use of hybrid inverter that converts DC into AC which is then fed directly into your home grid system.
Installing on-grid system is not very complicated however you should know when and how you can install these inverters.
- Using a grid-tied system might not be effective at night. Hybrid inverters do not have the capacity to hold charge to be used during the night. You will therefore be forced to use electricity at night which might be expensive.
- If you live in areas where the sun is not reliable, it would’ve best if you installed solar battery.
Although hybrid inverters connected to a grid might not be effective during the night, you can connect the inverter to the main electricity line for such occasions.
What is the difference between hybrid and battery inverters?
Both hybrid and battery inverters perform the same function. However, hybrid inverter is more advanced than battery inverter.
To differentiate between the two, we will create a side-by-side table showcasing their differences.
|Specification||Hybrid inverter||Solar Inverter|
|Basic||Made by merging a solar inverter, battery inverter and other solar PV components||Used with batteries|
|Use with a charge controller||Comes with an inbuilt charge controller||Usually used with MPPT charge controller|
|Installation||Can work without a solar battery||Cannot work without a solar battery|
|Types||Basic hybrid inverter Multi-mode hybrid inverter All-in-one hybrid energy storage system AC-Coupled Hybrid and Off-Grid Systems||Lead Acid Batteries Maintenance Free Batteries Tubular Batteries|
Basics and installation: Hybrid Inverters Vs. Battery Inverters
Hybrid inverters are inverters made by merging solar inverter + battery inverter. They also have inbuilt charge controller. You therefore do not need to use with an external charge controller.
Hybrid Inverters can be connected directly to a solar grid without a solar battery. You can also connect with battery backup.
Battery Inverters on the other hand are used with solar batteries. They work best connected to a solar battery and MPPT charge controller.
Types: Hybrid Inverters Vs. Battery Inverters
Hybrid Inverters come in four different types;
- Basic hybrid inverters
- Multi-mode hybrid Inverters
- All-in-one hybrid inverters
- AC-Coupled Hybrid and Off-Grid Systems
Battery Inverters on the other hand comes in three different types;
- Lead-Acid Batteries
- Maintenance Free Batteries
- Tubular Batteries
Each type of the Inverters mentioned above have unique features and can be used in specific situations.
What are available solar inverters?
Solar Inverters are the commonly used types of inverters in the solar world. They are classified into four different categories: Stand alone solar inverters, Grid-tied solar inverters, Battery backup inverters, and intelligent hybrid inverters.
Over the years, these inverters have been advanced with most of this solar inverters achieving a more than 95% efficiency. The list below consist of the four types of solar inverters in the market with their respective efficiency.
- String inverter: They come with a power of 150kWp and a 98% efficiency.
- Central inverter: These inverters have a power of over 80kWp and an efficiency of 98.5%.
- Micro inverters: These inverters comes with a module power range and an efficiency of between 90-97%.
- DC/DC converter: They also come with a module power range and a higher efficiency of 99.5%
You can read this PDF to find out more about these solar inverters.
How to connect an inverter to the solar panel?
Connecting a solar inverter to a solar panel is a very straightforward process. You will however need to know a few things when doing the installation.
The step-by-step process given below assumes you have a solar kit already. Otherwise, you will need to deal with that first.
Step 1: Install your solar panels
Depending on the number of solar panels you want, you can install them either in series or parallel.
Series installation increases the voltage while keeping the amps steady. This is usually done to match the solar battery.
A parallel installation keeps the voltage steady and increases the amps. In our case, we will use parallel installation.
Connect the negative lead of one solar panel to the positive module and the positive to the negative. The plugs are provided with the kit.
Step 2: Connect the solar panel to the inverter
The cables for the connection are provided. However, if the solar panel is at a distance, you will need to extend the cables.
Connect the plugs to the right input and ensure the wiring is tight otherwise you will deal with a no voltage issue.
Once the connection is done, the solar panel starts to send current to the inverter provided the sun is out.
Measure the voltage produced to see if it can run your home. Otherwise, you might need to add solar panels.
Not all solar PV systems need a solar battery to run. However, having a solar battery will improve your efficiency with the solar PV system.
A solar battery provides backup for charge. This charge can be used to run your appliances at night.
Since solar panels produce energy in form of DC, an inverter is necessary in all systems. It converts DC into AC.
The guide above has all the information you need about different inverters and how they work.
Eng. Matthew Joseph Nandirio is the Founder of walkingsolar.
After graduating from the University of Houston in 2002, matt started working as an electrical and electronic engineer for several multi-national solar energy companies.
He has a wide range of experiences including solar system requirement analysis, planning, maintaining, debugging and even solar device development through research.
He now shares his 20 years of expertise through his articles on the walkingsolar website.
Further, he is also the author of two books on Solar Technology, “Solar Power for Villages” and “DIY Solar System for Dummies”.